WO2012168983A1

WO2012168983A1 - Charging device

Info

Publication number: WO2012168983A1
Application number: PCT/JP2011/003312
Authority: WO
Inventors: 大澤　孝
Original assignee: 三菱電機株式会社
Priority date: 2011-06-10
Filing date: 2011-06-10
Publication date: 2012-12-13
Also published as: JPWO2012168983A1; JP5546685B2

Abstract

The present invention relates to a charging device (1) that charges a battery (3) for powering an electric automobile and uses an alternating current power source (2) as a power source. In order to achieve a high power-factor charging device using a simple configuration where the alternating current power source (2) and the battery (3) are mutually insulated, the device is provided with a power source rectifier unit (5) that rectifies the alternating current power source (2) to produce direct current output; a plurality of circuit block units (7-1 to 7-N), each of which comprises a transformer with a primary winding that also acts as a coil for improving efficiency and a secondary winding that insulates the alternating current power source (2) and the vehicle, a field-effect transistor (FET) that acts as a switching element, a rectifying diode, and a smoothing capacitor, wherein ON/OFF operation of the FET causes a prescribed direct current power from the direct current output of the power source rectifier unit (5) to be output; and a control unit for controlling the ON/OFF operation of the FET in each of the plurality of circuit block units (7-1 to 7-N). In addition, the primary-side structures of the plurality of circuit block units (7-1 to 7-N) are connected in parallel and the secondary-side structures of the plurality of circuit block units (7-1 to 7-N) are connected in series.

Description

Charger

The present invention relates to a charging device for charging a power battery such as an electric vehicle.

Demand for electric vehicles is increasing due to the acceptance of low carbon dioxide emissions in the trend of reducing global warming gas emissions. A power (on-vehicle) battery mounted on an electric vehicle is charged by an external AC power source using a charging device. In such a charging device, a power factor improving coil (reactor) for efficiently taking in electric power from an AC power source, an insulating transformer, a switching element, and a diode for insulating the AC power source from a power battery are used. .

For example, Patent Document 1 includes a reactor (coil) on the AC power supply side and a switch that supplies current to the reactor, and a switch that supplies current to the transformer and the primary winding of the transformer on the output side. A power converter is described in which the power factor is brought close to 1 by alternately operating the switches. This power converter uses a reactor and a transformer for power factor improvement and insulation. A configuration is also disclosed in which three-phase alternating current is used as a power source, power is input from three phases to three power converters, and three outputs are connected in parallel.

Patent Document 2 discloses a power factor correction circuit (PFC; Power Factor Correction) configured by a boost chopper circuit, an isolated DC / DC converter (second power conversion circuit), and an output voltage when a power supply voltage is lowered. A voltage drop protection device having an auxiliary low voltage backup unit is disclosed.
Patent Document 3 discloses a converter power supply circuit including a plurality of chopper circuits each including a choke coil, a switching transistor, and a diode, and connecting these chopper circuits in parallel. This converter power supply circuit operates the switching elements of a plurality of chopper circuits connected in parallel at the same frequency so that their drive timings do not overlap.

Patent Document 4 discloses a three-phase power factor correction circuit in which a power factor is improved by using a flyback transformer. In this circuit, the secondary winding side components of the transformer are connected in parallel to synthesize and smooth the flyback current. In Patent Document 4, the control circuit for controlling the driving of the circuit is an insulation type in which the primary side and the secondary side are electrically separated, or each of the switching elements of a plurality of inverter circuits has a phase difference. Are also described, and the configuration corresponding to a single-phase AC power supply is also described.

Furthermore, the conventional charger described in Patent Document 5 is a charger that shares a commercial power source and a regenerative power source (commercial regenerative common charger), and each battery is charged by each DC / DC converter. The regenerative current of the drive (regenerative) motor is used for charging via the DC / DC converter with respect to the series-connected battery array mounted on the vehicle. Patent Document 5 also discloses a configuration in which a high power factor AC / DC converter is provided separately from the DC / DC converter in charging from a commercial power source.

Japanese Unexamined Patent Publication No. 1-1117654 JP 2005-261118 A JP 2006-187140 A JP 2010-17047 A JP-A-11-113185

Conventionally, individual circuit technologies have been matured for power factor improvement and insulation.
However, a charging device for an electric vehicle requires characteristics corresponding to the battery voltage that varies depending on the environment of the local AC power supply and the amount of stored electricity when the vehicle is charged at the destination. For example, when a power supply voltage and an output voltage having poor conditions are combined, a high voltage is applied to the switching element or the rectifier diode, and therefore it is necessary to use a switching element or rectifier diode having a high rated voltage. In addition, the charging device for electric vehicles has a large capacity, and the parts to be used are inevitably parts having a high current rating.

Furthermore, since each element used in the charging apparatus needs to operate at high speed, the switching element or the rectifier diode having a high rated voltage is likely to be increased in size and cost.
For example,

Patent Documents

1 and 2 have a configuration in which a coil and a transformer are combined, and Patent Document 4 has a configuration in which a transformer is used. Therefore, when both the power supply voltage and the output voltage are high, a switching element or a rectifier diode is used. The voltage applied to can be high.
Therefore, it is necessary to use a switching element or a rectifier diode having a sufficiently high rated voltage for a charging device for an electric vehicle that can be charged in any power supply environment.

Further, in Patent Document 3, since a booster circuit using a coil is configured, an AC power source and a power (on-vehicle) battery cannot be insulated, and a low voltage battery is charged from a high voltage AC power source. This is not preferable as a charging device for an electric vehicle.
The charger described in Patent Document 5 is configured to charge individual batteries connected in series with each charger. This charger uses a separate AC / DC converter that improves the independent power factor, and no consideration is given to reducing the number of components, and the voltage applied to the switching element or rectifier diode can be reduced. There is no ingenuity to reduce. In addition, the number of wires connected to charge each battery is large, and each wire needs to be thick enough to carry a large current. It is difficult to arrange.

The present invention has been made to solve the above-described problems, and an object thereof is to obtain an inexpensive and small charging device with a simple configuration.

A battery charger for an electric vehicle according to the present invention is a charging device for charging an operating battery mounted on a vehicle with an AC power source, a rectifying unit for rectifying the AC power source into a DC output, and for power factor improvement A transformer having a primary winding that also serves as a coil and a secondary winding that insulates the AC power supply from the vehicle, a switching element that intermittently passes a current flowing through the primary winding of the transformer, and a secondary winding of the transformer that are output A plurality of circuit block units each configured to output a predetermined DC power from a DC output of the rectification unit by an ON / OFF operation of the switching element, the diode being configured to rectify the current and a smoothing capacitor that stores and smoothes the current output from the diode; A control unit that controls the on / off operation of the switching element included in each of the plurality of circuit block units. Connect the configuration of the primary side of the block portion in parallel, and the plurality of the configuration of the secondary side of the circuit block portion respectively connected in series.

According to the present invention, there is an effect that an inexpensive and small-sized charging device can be provided with a simple configuration.

It is a figure which shows the step-up circuit block of various structures, and its operation characteristic. It is a figure which shows the structure of the charging device which concerns on Embodiment 1 of this invention. It is a figure which shows the structure of the charging device which concerns on Embodiment 2 of this invention. It is a figure which shows the structure of the charging device which concerns on Embodiment 3 of this invention. It is a figure which shows the other structure of the charging device which concerns on Embodiment 3. FIG. It is a figure which shows another structure of the charging device which concerns on Embodiment 3. FIG. It is a figure which shows the structure of the charging device which concerns on Embodiment 4 of this invention. It is a figure which shows the structure of the charging device which concerns on Embodiment 5 of this invention. It is a figure which shows the structure of the charging device which concerns on Embodiment 6 of this invention.

Hereinafter, in order to describe the present invention in more detail, modes for carrying out the present invention will be described with reference to the accompanying drawings.
Embodiment 1 FIG.
FIG. 1 is a diagram showing booster circuit blocks of various configurations and their operating characteristics, showing operation signals of FETs (field effect transistors) that are switching elements, applied voltage waveforms of FETs, and applied voltage waveforms of rectifier diodes. Yes.
In the circuit block shown in FIG. 1A, the current flowing through the coil is interrupted by the FET, and when the FET is turned on, the magnetic energy stored in the coil and the core is discharged when the FET is turned off. It has a boost power supply configuration. In this circuit, electric power can be output even at the timing when the power supply voltage drops during one AC cycle, and the output voltage can be boosted with a high power factor.

In this circuit, the voltage applied to the FET is substantially an output voltage, and the voltage applied to the rectifier diode is also an approximate output voltage. That is, when the power supply voltage is 100 V and the output voltage is 200 V, the voltage applied to the FET and the rectifier diode is approximately 200 V, as shown in FIG.
For example, when the maximum voltage of the AC power supply is 250 Vrms (the output voltage of the rectifier is 350 Vdc) and the maximum voltage of the battery for the electric vehicle is 400 Vdc, the maximum voltage applied to the FET and the rectifier diode is 400 V, A 400V compatible FET and rectifier diode can be used.
However, as described in Patent Document 3, in this circuit configuration, the AC power supply and the battery (on-vehicle equipment) cannot be insulated, and a battery of, for example, 80 Vdc having a voltage lower than the power supply voltage is charged from, for example, a 250 Vrms AC power supply Cannot be used as a battery charger for electric vehicles.

In the circuit block shown in FIG. 1 (b), the current flowing in the primary winding of the transformer is interrupted by the FET. In other words, when the FET is on, a flyback power supply is constructed that discharges the magnetic energy stored in the transformer primary winding and core to the transformer secondary winding when the FET is turned off. Yes. In this circuit configuration, electric power can be output even at the timing when the power supply voltage decreases in one cycle of alternating current, and the voltage is increased or decreased at a high power factor, and the primary side and the secondary side are output. Insulation can be realized simultaneously.

In this circuit, when the primary and secondary turns ratio of the transformer is 1: n, the voltage applied to the FET is approximately ((output voltage / n) + power supply voltage), and is applied to the rectifier diode. Is approximately (output voltage + (n × power supply voltage)). That is, when the power supply voltage is 100 V, the output voltage is 200 V, and n = 1, as shown in FIG. 1B, the voltages applied to the FET and the rectifier diode are approximately 300 V, respectively.

For example, when the maximum voltage of the AC power supply is 250 Vrms (the output voltage of the rectifying unit is 350 Vdc), the maximum voltage of the battery for the electric vehicle is 400 Vdc, and n is 1, the maximum voltage applied to the FET is 400 V / 1 + 350 V = 750V, and the maximum voltage applied to the rectifier diode is 400V + 350V / 1 = 750V.
In this case, FETs and rectifier diodes corresponding to 750 V or more must be used, but FETs and diodes corresponding to the voltages, particularly FETs and diodes that have a high operating speed and can carry a large current, Since there are few general purpose things and there exists a tendency to enlarge, it is difficult to select a suitable thing from a viewpoint of the size and cost of the apparatus when commercialized.

In the circuit shown in FIG. 1 (c), a plurality of circuit blocks using a flyback transformer that doubles as a power factor improving coil and an insulation are connected in parallel on the primary side of the transformer. It is configured by connecting in series. In this configuration, the power rating of each transformer, FET, and rectifier diode is ½ compared to the circuit shown in FIG. Therefore, each transformer, FET, and rectifier diode can have a low rated voltage and can be small.

In this circuit, the voltage applied to the FET is approximately ((output voltage / 2n) + power supply voltage), and the voltage applied to the rectifier diode is approximately (output voltage / 2 + (n × power supply voltage)). is there. That is, when the power supply voltage is 100 V, the output voltage is 200 V, and n = 1, the voltage applied to the FET and the rectifier diode is approximately 200 V as shown in FIG.

For example, when the maximum voltage of the AC power supply is 250 Vrms (the output voltage of the rectifying unit is 350 Vdc), the maximum voltage of the battery for the electric vehicle is 400 Vdc, and n is 1, the maximum voltage applied to the FET is 400 V / 2 + 350 V = 550V, and the maximum voltage applied to the rectifier diode is 400V / 2 + 350V / 1 = 550V.

When the number of the circuit blocks is N, the power rating of each transformer, FET, and rectifier diode is 1 / N compared to the circuit shown in FIG. Accordingly, each transformer, FET, and rectifier diode can be further small in rated voltage and small.

In this circuit, when the primary and secondary turns ratio of each transformer is 1: n, the voltage applied to the FET is approximately ((output voltage / (N × n)) + power supply voltage). The voltage applied to the rectifier diode is approximately (output voltage / N + (n × power supply voltage)).
Therefore, when the maximum voltage of the AC power supply is 250 Vrms (the output voltage of the rectifying unit is 350 Vdc), the maximum voltage of the battery for the electric vehicle is 400 Vdc, n is 1, and N is 8, the maximum voltage applied to the FET is 400 V / Since 8 + 350V = 400V, and the maximum voltage applied to the rectifier diode is 400V / 8 + 350V / 1 = 400V, a FET and a rectifier diode having a voltage rating substantially equivalent to the configuration of FIG. 1A can be used.

Thus, if the number of the circuit blocks is increased and the primary side of the transformer is connected in parallel and the secondary side is connected in series, the FET and the rectifier diode with high versatility and low rated voltage are provided. Can be used, and suitable selection is possible from the viewpoint of the size and cost of the apparatus when it is commercialized.

FIG. 2 is a diagram showing a configuration of the charging apparatus according to Embodiment 1 of the present invention. In FIG. 2, a charging device 1 according to Embodiment 1 is a device that charges an electric vehicle battery 3 from an AC power source 2, and includes a power rectifier 5, a PFC (power factor improvement) / DC / DC converter 6. The smoothing capacitor voltage input unit 8 and the control unit 9 are provided. The electric vehicle battery 3 is connected to a high voltage load 4 such as a power motor of the electric vehicle.

The power supply rectification unit 5 includes diodes 5-1, 5-3, and 5-2, 5-4 connected for full-wave rectification. The anode terminals of the diodes 5-1 and 5-2 serve as low-potential side outputs and are connected to the source terminals of the FETs of the circuit block units 7-1 to 7-N, respectively. Each cathode terminal 4 serves as a high potential side output and is connected to one end (terminal not connected to the FET) of the primary winding of each transformer of the circuit block units 7-1 to 7-N. Furthermore, one output terminal of the AC power source 2 is connected to the connection point of the diodes 5-1 and 5-3, and the other output terminal of the AC power source 2 is connected to the connection point of the diodes 5-2 and 5-4. Yes.

The PFC / DC / DC converter 6 is a component that generates a DC voltage for an electric vehicle (for power) that varies from about 80 Vdc to about 400 Vdc, using various types of AC power supply 2 such as a 100 Vrms system or a 200 Vrms system as a power source. There are a plurality (N) of circuit block units 7-1 to 7-N.
Each of the circuit block units 7-1 to 7-N is a DC / DC converter including a transformer, a FET (field effect transistor), a rectifier diode, and a smoothing capacitor. The transformers of the circuit block units 7-1 to 7-N are flyback type transformers having a primary winding that also serves as a power factor improving coil and a secondary winding that insulates the AC power source 2 from the vehicle power source. It is a transformer. The FET is a switching element that intermittently supplies an energization current to the primary winding of the transformer. The rectifier diode rectifies the output current from the secondary winding of the transformer. The smoothing capacitor stores and smoothes the output current of the rectifier diode.
In addition, as shown in FIG. 1, the circuit block units 7-1 to 7-N are composed of primary components of each transformer (one terminal of the transformer primary winding (the terminal not connected to the FET)). And the source terminal of the FET) are connected in parallel, and the secondary side component (two output terminals via a smoothing capacitor) are connected in series.

The smoothing capacitor voltage input unit 8 inputs a voltage applied to each of the smoothing capacitors of the circuit block units 7-1 to 7-N and outputs the voltage to the control unit 9.
The control unit 9 is a component that controls the operation of the circuit block units 7-1 to 7-N. The circuit block FET drive signal output to the gate terminals of the FETs of the circuit block units 7-1 to 7-N. By controlling the on / off operation of each FET to store magnetic energy in the transformer and releasing it, the current generated in the transformer is rectified by a rectifier diode and smoothed by a smoothing capacitor to generate a DC voltage.
Further, in the first embodiment, the control unit 9 causes each of the circuit block units 7-1 to 7-N to equalize the voltages of the respective smoothing capacitors obtained via the smoothing capacitor voltage input unit 8. The on / off operation (period and duty) of the FETs is operated, and control for intermittent operation and PWM control are performed for each FET.

As shown in FIG. 1C and FIG. 2, in the present invention, a plurality of circuit block units including an insulating transformer, FET, rectifier diode, and smoothing capacitor that also serve as a power factor improving coil are used. A set of charging devices is configured. With this configuration, in each of the circuit block units 7-1 to 7-N, FETs and rectifier diodes having a low general-purpose rated voltage are used, and a power factor improving coil is not used. An inexpensive charging device can be realized with a simple configuration. In addition, since the charging device 1 has two output terminals for charging the battery 3 for electric vehicles (power), it is necessary to arrange a plurality of thick wirings connected to individual batteries as in Patent Document 5. There is no structure, and it becomes a structure with a high mechanical freedom of design.

In the circuit block units 7-1 to 7-N, various transistors such as IGBT (Insulated Gate Bipolar Transistor) are used in addition to the FET having a high switching speed, and the rectifier diode has a fast reverse recovery time. A recovery diode (FRD) may be used. Generally, when the circuit voltage of a device using a switching element and a rectifier diode exceeds 500 Vdc, the switching elements and rectifier diodes having a rated voltage corresponding to the circuit voltage are remarkably reduced, and the degree of freedom in element selection is reduced. In addition, when the circuit voltage increases, some electrical characteristics such as switching speed and reverse recovery time may be traded off to ensure the withstand voltage of each element. The degree of freedom is also limited. Furthermore, the cost of an element with a small distribution quantity is generally high.
Similarly, the smoothing capacitor has a filter function that outputs a DC current with less ripple to the battery 3 while improving the power factor of the power supply. Therefore, the conventional charging device absorbs a ripple having twice the frequency of the AC power supply 2. Therefore, a capacitor having a high withstand voltage and a large capacity (for example, an electrolytic capacitor or a super capacitor) has to be used. As described above, conventionally, the smoothing capacitor also has a low degree of freedom in element selection, and the cost is inevitably high.

Therefore, in the present invention, as shown in FIG. 1C and FIG. 2, a plurality of circuit block units 7-1 to 7-N functioning as DC / DC converters are used, and the primary side of each transformer is used. These components are connected in parallel, and the secondary components are connected in series to form a set of charging devices. With this configuration, a general-purpose element having a low rated voltage can be used for each circuit block unit, and the degree of freedom for selecting an element that can naturally operate at high speed is improved. For example, if the switching frequency of the DC / DC converter configuration can be increased, a small coil or transformer can be used.

The present invention is equivalent to a transformer, FET, and smoothing capacitor that constitute a set of charging devices, but each transformer, FET, and smoothing capacitor can be reduced in size. As a result, the entire charging device 1 can be reduced in size.
In particular, when each element is reduced in size, each element can be easily fixed with a simple fixing means, which is suitable for an in-vehicle charging apparatus in which a large vibration may be applied.
Furthermore, since a general-purpose transformer, FET, and smoothing capacitor having a low rated voltage are low in cost, the charging device 1 can be configured at low cost.

In the first embodiment, the control unit 9 is configured so that the voltages of the smoothing capacitors in the circuit block units 7-1 to 7-N input via the smoothing capacitor voltage input unit 8 are substantially equal. The on / off operation (cycle and duty) of each FET of the circuit block units 7-1 to 7-N is controlled. By controlling in this way, the voltages applied to the smoothing capacitors in the circuit block units 7-1 to 7-N vary, and the voltages applied to some of the smoothing capacitors become excessive, causing the smoothing to occur. It is possible to prevent the capacitor from being deteriorated and further destroyed. As a result, a highly reliable charging device that does not place a burden on the smoothing capacitor can be configured.

As described above, in the first embodiment, the AC power source 2 is a charging device 1 that charges an operating battery mounted on a vehicle, and the power source rectifying unit 5 rectifies the AC power source 2 into a DC output. A transformer having a primary winding that also serves as a power factor improving coil and a secondary winding that insulates the AC power source 2 from the vehicle, an FET that is a switching element for intermittently passing a current flowing through the primary winding of the transformer, and a transformer The rectifier diode that rectifies the current output from the secondary winding of the rectifier and the smoothing capacitor that stores and smoothes the current output from the rectifier diode. A predetermined DC power is obtained from the DC output of the power supply rectifier 5 by the ON / OFF operation of the FET. Controls the ON / OFF operation of the FETs included in each of the plurality of circuit block units 7-1 to 7-N and the plurality of circuit block units 7-1 to 7-N. A plurality of circuit block units 7-1 to 7-N are connected in parallel to each other, and a plurality of circuit block units 7-1 to 7-N are configured on the secondary side. Are connected in series. Since it comprised in this way, the cheap and small-sized charging device 1 can be provided by simple structure.

Further, according to the first embodiment, the control unit 9 performs the on / off operation (period and duty) of the FET so that the voltages applied to the smoothing capacitors of the circuit block units 7-1 to 7-N are substantially equal. ) To control. In particular, a smoothing capacitor voltage input unit 8 for inputting a voltage of a smoothing capacitor included in each of the circuit block units 7-1 to 7-N is provided, and the control unit 9 receives each smoothing capacitor input by the smoothing capacitor voltage input unit 8. Are controlled to be substantially equal. By doing so, the voltages applied to the smoothing capacitors in the circuit block units 7-1 to 7-N are different, and some of the smoothing capacitors are deteriorated or destroyed due to overvoltage. Thus, a highly reliable charging device that does not place a burden on the smoothing capacitor can be configured.

Embodiment 2. FIG.
FIG. 3 is a diagram showing a configuration of a charging apparatus according to Embodiment 2 of the present invention. As illustrated in FIG. 3, the charging device 1 </ b> A according to the second embodiment includes a switching element application voltage input unit 10 instead of the smoothing capacitor voltage input unit 8 in the configuration of the first embodiment.
The control unit 9A is configured so that the voltages (source-drain voltages) applied to the FETs of the circuit block units 7-1 to 7-N input via the switching element application voltage input unit 10 are substantially equal. The on / off operation (cycle and duty) of each FET in the circuit block units 7-1 to 7-N is controlled.

If the voltages (source-drain voltages) applied to the FETs of the circuit block units 7-1 to 7-N are equalized, the voltages applied to the FETs of the circuit block units 7-1 to 7-N When the overvoltage is applied to a part of the FETs, the FETs can be prevented from being deteriorated and further destroyed.
The voltage applied to the FET has a correlation with the voltage applied to each smoothing capacitor of the circuit block units 7-1 to 7-N. Accordingly, if the voltages applied to the FETs of the circuit block units 7-1 to 7-N are made substantially equal, the voltages applied to the smoothing capacitors can be made equal. In other words, the voltages applied to the smoothing capacitors in the circuit block units 7-1 to 7-N vary, and when an overvoltage is applied to some of the smoothing capacitors, the smoothing capacitors deteriorate and further break down. Can also be prevented.

The source-drain voltage of the FET may be measured after being converted to a direct current by a diode and smoothed by a capacitor as shown in FIG. 3, but the voltage when the FET is off is an A / D converter. Or the like may be sampled and measured.

As described above, according to the second embodiment, the switching element applied voltage input unit 10 for inputting the voltage applied to the FETs included in each of the plurality of circuit block units 7-1 to 7-N is provided, and is controlled. The unit 9A controls so that the voltages applied to the respective FETs input by the switching element applied voltage input unit 10 are substantially equal. With this configuration, it is possible to provide a highly reliable charging device 1A that does not place a burden on the FETs and smoothing capacitors in each of the circuit block units 7-1 to 7-N.

Embodiment 3 FIG.
FIG. 4 is a diagram showing a configuration of a charging apparatus according to Embodiment 3 of the present invention. In FIG. 4, a charging device 1 </ b> B according to Embodiment 3 is a device that charges an electric vehicle battery 3 from an AC power supply 2, and includes a power supply rectification unit 5 </ b> A, a PFC (power factor improvement) / DC / DC converter unit 6. The control unit 9B and the phase input unit 12 (a part of the control unit 9B) are provided.
The power supply rectification unit 5A includes diodes 5-1, 5-3, and 5-2, 5-4 connected for full-wave rectification, and further, FET 11 is connected to both ends of each of the diodes 5-1 to 5-4. The source terminals and drain terminals of -1 to 11-4 are connected to each other. Similarly to the first embodiment, the anode terminals of the diodes 5-1 and 5-2 are output on the low potential side and are connected to the source terminals of the FETs of the circuit block units 7-1 to 7 -N. The cathode terminals of the diodes 5-3 and 5-4 are output on the high potential side and are connected to one end of the primary winding of each transformer of the circuit block units 7-1 to 7-N. Furthermore, one output terminal of the AC power source 2 is connected to the connection point of the diodes 5-1 and 5-3, and the other output terminal of the AC power source 2 is connected to the connection point of the diodes 5-2 and 5-4. Yes.
The phase input unit 12 inputs the phase of the AC power supply 2 and outputs it to the control unit 9B.
The control unit 9B controls the on / off operation of the FETs 11-1 to 11-4 of the power supply rectifying unit 5A in accordance with the phase of the AC power supply 2 input via the phase input unit 12.

When the diodes 5-1 to 5-4 are used for rectification of the power source current of the AC power source 2 as in the first and second embodiments, 0.7 to 1 V per diode is applied to the diodes 5-1 to 5-4. About a voltage drop occurs. For this reason, when a large current is applied, loss due to this voltage drop increases.
Therefore, FETs 11-1 to 11-4 are provided as switching elements for short-circuiting between the anode and cathode terminals of the diodes 5-1 to 5-4 of the power supply rectifier 5, and the on / off operation is controlled in synchronization with the phase of the power supply voltage. (Synchronous rectification). Since the voltage drop of each of the FETs 11-1 to 11-4 is lower than the voltage drop of each of the diodes 5-1 to 5-4, this configuration can reduce the loss in the power supply rectifying unit 5A.

4 shows the case where the FETs 11-1 to 11-4 for short-circuiting between the anode and cathode terminals of the diodes 5-1 to 5-4 are provided, the diodes 5-1 to 5-4 and A similar effect can be obtained by providing a switching element having a diode function (rectifying function) instead of the FETs 11-1 to 11-4.

FIG. 5 is a diagram illustrating another configuration of the charging apparatus according to Embodiment 3. In FIG. The power supply rectification unit 5B of the charging device 1C shown in FIG. 5 is a low-frequency full-wave rectification bridge circuit composed of the diodes 5-1 to 5-4 of the power supply rectification unit 5 of the first and second embodiments. Instead of the diodes 5-1 and 5-2 on the potential side, FETs 13-1 and 13-2 having parasitic diodes are provided. The control unit 9B controls (synchronous rectification) the on / off operations of the FETs 13-1 and 13-2 in synchronization with the phase of the power supply voltage of the AC power supply 2, so that the low-potential side diodes 5-1 and 5-2 Loss due to a forward voltage drop that occurs in
In addition, instead of the FETs 13-1 and 13-2 having the parasitic diodes, freewheeling diodes and IGBTs are provided, and the control unit 9B controls the on / off operation of the IGBTs in synchronization with the phase of the power supply voltage of the AC power supply 2 ( The same effect can be obtained even when synchronous rectification is performed.

Further, in the example shown in FIG. 5, the phase input unit 12 in the control unit 9B is shown in order to explain the on / off operation of the switching element of the power supply rectification unit 5B in the control unit 9B. The phase input unit 12 of the part that controls the on / off operation of the switching element of the power supply rectification unit 5B) includes a part corresponding to the phase input unit 12 that inputs the AC power supply 2 via the resistors R1 and R2, and the resistors R1 and R1, respectively.

Comparators

12a and 12b for comparing the power supply voltage input via R2 and the comparison direct current voltage of the comparison power supply 12c, respectively. The comparator 12a outputs a high-level or low-level voltage by comparing the power supply voltage input via the resistor R1 and the comparison DC voltage of the comparison power supply 12c, and the comparator 12b passes through the resistor R2. A high level or low level voltage is output by comparing the input power supply voltage with a comparative DC voltage.
For example, when the power supply voltage on the resistor R1 side of the AC power supply 2 becomes equal to or higher than the comparison DC voltage, the output of the comparator 12a becomes high level and the FET 13-2 is turned on, and the power supply voltage on the resistor R2 side of the AC power supply 2 is compared. When the voltage becomes higher than the DC voltage for output, the output of the comparator 12b becomes a high level, and the FET 13-1 is turned on, whereby a low-potential side diode (diode 5-1, 5 -2) can be short-circuited in synchronization with the phase of the power supply voltage of the AC power supply 2, and synchronous rectification with less loss can be performed.

FIG. 6 is a diagram showing still another configuration of the charging apparatus according to Embodiment 3. In FIG. The power supply rectification unit 5C of the charging device 1D shown in FIG. 6 also includes FETs 13-3 and 13-4 having parasitic diodes for the diodes 5-3 and 5-4 on the high potential side of the power supply rectification unit 5B shown in FIG. Instead,

pulse transformers

14a and 14b are provided as drivers for driving them. The

pulse transformers

14a and 14b output control signals corresponding to the outputs of the

comparators

12a and 12b to the gate terminals of the FETs 13-3 and 13-4, and turn them on / off. With this configuration, it is possible to further reduce a loss due to a forward voltage drop that occurs in a diode on the high potential side (corresponding to diodes 5-3 and 5-4).
In addition, instead of the FETs 13-3 and 13-4 having the parasitic diode, a freewheeling diode and an IGBT are provided, and the control unit 9B controls the on / off operation of the IGBT in synchronization with the phase of the power supply voltage of the AC power supply 2 ( The same effect can be obtained even when synchronous rectification is performed.
For driving the high potential side FETs 13-3, 13-4 or IGBT, a level shift circuit or an insulated driver circuit can be used in addition to the pulse transformer.

5 and 6 show the case where the phase input unit 12 in the control unit 9B is configured by a circuit using the

comparators

12a and 12b. However, other circuit configurations or digital circuits using a CPU may be used. It may be configured. For example, the CPU takes in the AC voltage of the AC power supply 2 via the A / D converter and controls the on / off operation of the switching elements such as the FETs 13-1 to 13-4 at an appropriate timing synchronized with the phase of the AC voltage. You can also.

The circuit configuration of the control unit 9B using the

comparators

12a and 12b of the phase input unit 12 or the CPU is simple because the low potential side output of the DC power source obtained by rectifying the power source voltage of the AC power source 2 can be used as a common potential. With a simple circuit, it is possible to control the on / off operation of the switching elements of the circuit block section and the switching elements for synchronous rectification.

As described above, according to the third embodiment, as shown in FIGS. 4 to 6, power supply rectifiers 5A to 5C include FETs with a rectifying function, or diodes and FETs that open and close the conduction between both ends. The control unit 9B inputs the phase of the AC power source 2 and controls the on / off operation of the FET in accordance with the phase of the AC power source 2. By doing in this way, the power loss of power

supply rectification part

5A, 5B, 5C which rectifies | straightens alternating current power supply can be reduced, and a charging device with high power supply efficiency is realizable with simple structure.

Embodiment 4 FIG.
FIG. 7 is a diagram showing a configuration of a charging apparatus according to Embodiment 4 of the present invention. The PFC / DC / DC converter unit 6B of the charging apparatus 1E shown in FIG. 7 includes circuit block units 7B-1 to 7B-N. Each of the circuit block units 7B-1 to 7B-N is a set of circuits in which a plurality of DC / DC converter circuits composed of an insulating transformer, FET, and rectifier diode that also serve as a power factor improving coil are connected in parallel. A block part is configured. Further, the control unit 9C controls the output voltage in each circuit block unit by controlling the on / off operation of the plurality of FETs in each circuit block unit according to the circuit block FET drive signal.
In FIG. 7, the configuration of each of the circuit block units 7B-2 to 7B-N is the same as that of the circuit block unit 7B-1, and is not described.

As described above, according to the fourth embodiment, as shown in FIG. 7, the circuit block units 7B-1 to 7B-N are connected to the primary winding and the AC power source 2 that also serve as a power factor improving coil. And a transformer having a secondary winding that insulates the vehicle, an FET that interrupts the current flowing through the primary winding of the transformer, and a diode that rectifies the current output from the secondary winding of the transformer. In the circuit block unit, a plurality of DC / DC converters that output predetermined DC power from the DC output of the power supply rectification unit 5 are connected in parallel by the on / off operation of the FET, and the currents output from the plurality of rectifier diodes are integrated. Then, it is smoothed by a smoothing capacitor to generate a DC voltage for each circuit block. With this configuration, an element having a lower rated power can be used as an element used for each DC / DC converter circuit in each circuit block.

Embodiment 5 FIG.
In the first to fourth embodiments described above, the control unit collectively controls the switching elements of the circuit block unit, but the AC power source 2 side (the input side of the own device) and the in-vehicle device side with respect to the circuit block unit (The output side of the device itself) is insulated and has different reference potentials, so that the voltage and current input circuits and feedback circuits in the control unit have a complicated configuration.
Therefore, in the fifth embodiment, as in the charging device 1F shown in FIG. 8, the control unit controls the on / off operation of the FETs of the circuit block units 7C-1 to 7C-N of the PFC / DC / DC converter unit 6C. FET drive control unit 9D-1 (first control unit) and circuit block units 7C-1 to 7C-N output voltage and output current feedback control unit 9D- 2 (second control unit). The control units 9D-1 and 9D-2 receive feedback signals from the control unit 9D-2 in order to electrically insulate them from each other so as to correspond to the AC power supply 2 side and the in-vehicle device side which are insulated from each other. Then, the signal is transmitted to the control unit 9D-1 through an insulating circuit configuration.

As an example of feedback of the output voltage, FIG. 8 shows a configuration using voltage dividing resistors Ra and Rb, a photocoupler 16, an error amplifier 17, and a comparison power supply 18 connected in series between output terminals of the device. In this configuration, the output voltage of the own device is divided by the voltage dividing resistors Ra and Rb and input to one of the input terminals of the error amplifier 17. The error amplifier 17 amplifies the difference between the voltage obtained by dividing the output voltage by the voltage dividing resistors Ra and Rb and the comparison DC voltage of the comparison power supply 18, and the current corresponding to the difference between the two voltages is used as the light emitting element of the photocoupler 16. To flow. A feedback signal having a value corresponding to the difference between both voltages is output from the light receiving element of the photocoupler 16 to the output F / B input terminal of the control unit 9D-1, and each circuit block unit 7C-1 is output according to the value of the feedback signal. Controls the on / off operation of the 7C-N FET. By operating the control units 9D-1 and 9D-2 as described above, the output voltage can be maintained at an arbitrary value.
In the above, feedback of the output voltage is given as an example. However, feedback of the output current can be similarly performed using a current sensor, and the output current can be maintained at an arbitrary value by a similar operation.
In FIG. 8, the configuration of each of the circuit block units 7C-2 to 7C-N is the same as that of the circuit block unit 7C-1, and is not described.
Further, as a power source for the control unit 9D-1, a power source generated from the AC power source 2 using a small-capacity DC / DC converter, or a power source configured by adding a power winding to a transformer provided in the circuit block unit Can be used.

Further, as shown in FIG. 8, between each circuit block unit 7C-1 to 7C-N and the power supply rectification unit 5 (high potential side output of the power supply rectification unit 5 and each circuit block unit 7C-1 to 7C-N A fuse 15 that melts due to overcurrent may be provided on one terminal of the primary winding of the transformer (between the terminal that is not connected to the FET). As a result, even if a failure occurs in which some of the circuit block portions of the circuit block portions 7C-1 to 7C-N are short-circuited, the failure is caused by the fuse 15 of the circuit block portion being blown. It is possible to avoid the circuit block unit from interfering with the operation of other circuit blocks. At this time, the other circuit block unit can supplement the operation of the failed circuit block unit and continue the charging operation.

As described above, according to the fifth embodiment, the control unit is divided into the control unit 9D-1 and the control unit 9D-2 that are insulated from each other as shown in FIG. -2 feeds back the output voltage signal output from the device itself to the battery 3 or the energized output current signal to the control unit 9D-1, and the control unit 9D-1 outputs the output voltage signal fed back from the control unit 9D-2. In addition, the battery 3 can be charged by controlling the on / off operation of the FETs provided in the plurality of circuit block units 7-1 to 7-N based on the output current signal, and a simple charging device 1F is realized. can do.

Embodiment 6 FIG.
FIG. 9 is a diagram showing a configuration of a charging apparatus according to Embodiment 6 of the present invention. As shown in FIG. 9, the charging device 1G according to the sixth embodiment includes a control unit 9E-1 that is a control unit on the AC power supply 2 side (an AC power supply side control unit), and an in-vehicle device 21 side. The controller 9E-2 is a controller (on-vehicle equipment side controller), and the controllers 9E-1 and 9E-2 are insulated and provided. The control unit 9E-1 is configured by using, for example, a dedicated IC or a microcomputer, and is supplied with power based on the output voltage (12V) of the in-vehicle battery 22 using an insulated control power source 19a. The on / off operation of each FET of the circuit block units 7D-1 to 7D-N of the PFC / DC / DC converter unit 6D is controlled. The control unit 9E-2 is configured by using, for example, a dedicated IC or microcomputer, and is supplied with power based on the output voltage (12V) of the in-vehicle battery 22 by the control power source 19b. Information on the current is transmitted to the control unit 9E-1.
In FIG. 9, the configuration of each of the circuit block units 7D-2 to 7D-N is the same as that of the circuit block unit 7D-1, and is not described.

The control units 9E-1 and 9E-2 share the insulated interface (I / F) 20 and exchange vehicle information with each other, so that the control unit 9E-2 transmits the vehicle information to the control unit 9E-1. In addition to controlling the PFC / DC / DC converter unit 6D with the output voltage and output current signal, etc., and appropriately operating the output voltage and output current, the input voltage transmitted from the control unit 9E-1 to the control unit 9E-2 In addition, it is possible to accurately perform system control including a fail operation performed by the in-vehicle device 21 using an input current signal or the like.
The control unit 9E-1 controls the PFC / DC / DC converter unit 6D (drives the FET of the circuit block unit) and inputs information on the input voltage and input current from the AC power source 2 and the control unit 9E-2. In addition to the transmission of the AC power supply information of the input such as the period and phase, the transmission to the control unit 9E-2, the driving of the synchronous rectification FET (see Embodiment 3) of the AC power supply 2, the control unit 9E- The input of the output voltage and the output current signal from 2 and the input of the operation / stop information and the fail information transmitted from the in-vehicle device 21 via the control unit 9E-2 are performed. In addition to the input of the output voltage and output current and the transmission of the input voltage and input current signal to the in-vehicle device 21, the control unit 9E-2 inputs the heat generation information of the component parts, the in-vehicle battery (12V) 22 Voltage input and AC power supply information input from the control unit 9E-1 are input and transmitted to the in-vehicle device 21. On the other hand, the operation / stop information from the in-vehicle device 21 and the charge current request value and the fail information are input and transmitted to the control unit 9E-1. The insulating I / F 20 uses a photocoupler that uses light or a transformer that uses magnetism.

A supplement is added below regarding the said insulation type control power supply 19a.
The control power supply has a capability of securing a sufficient low voltage power supply for the control unit 9E-1 even when a low voltage 100Vrms power supply is used as the AC power supply 2, and also when a high voltage 200Vrms is used as the power supply. Since it is necessary to supply similar electric power, deterioration of power supply efficiency is inevitable. In addition, since a device compatible with a high voltage power source must be used, a sufficient margin in terms of power is required for the components to be used.
However, as shown in FIG. 9, by using an insulated control power supply 19a that generates a power supply for the control unit 9E-1 on the AC power supply 2 side based on the output voltage of the in-vehicle battery 22, it is relatively stable. It is possible to realize a power source with high power efficiency using the DC voltage 12V of the on-vehicle battery 22 using an element with a low rated voltage. In addition, the operation of the control unit 9E-1 and the input / output of information are performed by setting the low potential side of the direct current rectified from the AC power supply 2 as a common potential in the same manner as in the third embodiment. An isolated power supply can be configured with a simple circuit. Incidentally, the charging operation to the electric vehicle from the AC power source 2 is performed when the in-vehicle device 21 is operating normally, that is, when the 12V voltage of the in-vehicle battery 22 is supplied. When power is not supplied, there is no need to operate the device itself to charge the battery 3.

As described above, according to the sixth embodiment, the control unit is divided into the control unit 9E-1 and the control unit 9E-2 that are insulated from each other, as shown in FIG. The control unit 9E-2 inputs information including the output voltage and output current of the device itself and outputs the information to the control unit 9E-1, and the control unit 9E-1 responds to the information input from the control unit 9E-2. The operation of the plurality of circuit block units 7-1 to 7-N is controlled. On the other hand, the control unit 9E-1 inputs information including an input voltage and an input current from the AC power source and outputs the information to the control unit 9E-2. The control unit 9E-2 inputs the information from the control unit 9E-1. Information is output to the in-vehicle device 21, and system control including the charging device is performed by the in-vehicle device 21. Since it comprised in this way, the charging device which can perform flexible control with a simple structure can be comprised.

In the first to sixth embodiments, the control unit shifts the operation timing of each FET in each circuit block unit. For example, each circuit block FET drive signal is transmitted so that each FET operates sequentially. Output to the FET in the circuit block. Thus, by sequentially outputting each FET drive signal and sequentially operating each circuit block unit, ripples of the power supply current and output current can be reduced, and noise on the power supply and output can be reduced. That is, it is possible to realize a charging device that is less affected by harmonics, noise, and the like on the AC power supply 2 and the battery 3.

In particular, in the configuration having a plurality of FETs (switching elements) in each circuit block portion as in the fourth embodiment, if the respective switching operations are shifted, the peak current of the charging current of the smoothing capacitor is suppressed, and the ripple current is reduced. Can be reduced. Thereby, the heat_generation | fever of a smoothing capacitor can be reduced and deterioration can be suppressed. Further, it is possible to use a capacitor having a small allowable ripple current, such as an electrolytic capacitor or a super capacitor.

In the present invention, within the scope of the invention, any combination of each embodiment, any component of each embodiment can be modified, or any component can be omitted in each embodiment. .

Since the charging device according to the present invention is a low-cost and small-sized charging device with a simple configuration, it is suitable for an in-vehicle charging device for charging a power battery such as an electric vehicle.

1, 1A to 1G charging device, 2 AC power supply, 3 battery, 4 load, 5, 5A to 5C power rectifier, 5-1 to 5-4 diode, 6, 6A to 6D PFC / DC / DC converter, 7 -1 to 7-N, 7A-1 to 7A-N, 7B-1 to 7B-N, 7C-1 to 7C-N, 7D-1 to 7D-N circuit block section, 8 smoothing capacitor voltage input section, 9 , 9A-9C, 9D-1, 9D-2, 9E-1, 9E-2 control unit, 10 switching element applied voltage input unit, 11-1 to 11-4 FET, 12 phase input unit, 12a, 12b comparator , 12c, 18 Comparative power supply, 13-1 to 13-4 FET with parasitic diode, 14a, 14b pulse transformer, 15 fuse, 16 photocoupler, 17 error amplifier, 19a, 19b control power , 20 insulated I / F, 21 vehicle apparatus, 22 a vehicle-mounted battery.

Claims

A charging device for charging a battery for operation mounted on a vehicle with an AC power source,
A rectifier that rectifies the AC power source into a DC output;
A transformer having a primary winding that also serves as a power factor improving coil and a secondary winding that insulates the AC power source from the vehicle, a switching element that intermittently passes a current flowing through the primary winding of the transformer, and the transformer And a smoothing capacitor that stores and smoothes the current output from the diode, and outputs a predetermined direct current power from the direct current output of the rectifier by the on / off operation of the switching element. A plurality of circuit block sections each outputting,
A control unit that controls the on / off operation of the switching element included in each of the plurality of circuit block units,
Connecting the primary side configurations of the plurality of circuit block units in parallel;
A charging device comprising a plurality of circuit block units connected on the secondary side in series.
2. The charging device according to claim 1, wherein the control unit controls the voltages of the smoothing capacitors included in each of the plurality of circuit block units to be substantially equal.
A smoothing capacitor voltage input unit for inputting a voltage of a smoothing capacitor included in each of the plurality of circuit block units;
The charging device according to claim 2, wherein the control unit controls the voltages of the smoothing capacitors input by the smoothing capacitor voltage input unit to be substantially equal to each other.
A switching element application voltage input unit for inputting a voltage applied to a switching element included in each of the plurality of circuit block units;
The charging device according to claim 2, wherein the control unit controls the voltages applied to the switching elements input by the switching element application voltage input unit to be substantially equal to each other.
The rectifying unit is configured to include a switching element with a rectifying function, or a switching element that opens and closes a diode and conduction at both ends thereof.
2. The charging device according to claim 1, wherein the control unit inputs the phase of the AC power supply and controls the on / off operation of the switching element in accordance with the phase of the AC power supply.
A plurality of transformers having a primary winding that also serves as a power factor improving coil and a secondary winding that insulates the AC power source from the vehicle, and a primary winding of the transformer. A plurality of switching elements for intermittently flowing current, and a plurality of diodes for rectifying the current output from the secondary winding of the transformer, and the outputs of the plurality of diodes output by the on / off operation of the switching elements 2. The charging device according to claim 1, wherein the charging devices are connected in parallel, and the currents output from the plurality of diodes are integrated and stored in smoothing capacitors of the individual circuit blocks.
The charging device according to claim 1 or 6, wherein the control unit controls the on / off operation of the switching elements respectively included in the plurality of circuit block units so that the operation timings of the switching elements are shifted from each other.
The control unit includes a first control unit and a second control unit that are insulated from each other.
The second control unit feeds back an output voltage, an output current, or the like output from the device itself to the first control unit,
The first control unit controls an on / off operation of a switching element included in each of the plurality of circuit block units based on an output voltage, an output current, or the like fed back from the second control unit. Item 2. The charging device according to Item 1.
The control unit includes an AC power supply side control unit and an in-vehicle device side control unit that are insulated from each other,
The AC power supply side control unit outputs information such as the input voltage and input current of the device itself to the in-vehicle device side control unit,
The in-vehicle device side control unit outputs information such as the output voltage and output current of the device itself to the AC power source side control unit,
The charging apparatus according to claim 1, wherein the AC power supply side control unit and the in-vehicle device side control unit perform respective operations according to input information.